1. Field of the Invention
This invention relates to surgical instruments more particularly relates to an improved blade locking mechanism for retractors.
2. Background Information
Retractors are used to hold an incision open when performing surgical procedures. A variety of retractors are used for example to perform heart bypass operations or operations such as laminectomies.
A retractor is generally comprised of a pair of arms parallel to each extending from a cross bar. One of the arms is preferably fixed on the end of the cross bar while the other is mounted for movement by a crank and gear mechanism along cross bar. The retractor is placed in an incision with the arms nearly closed and the movable arm cranked open to spread and hold an incision open during surgery. One such surgical retractor is shown and described in U.S. Pat. No. Design 361,381 issued to the same inventors as the device disclosed herein.
After placement of these retractors, retractors blades are attached and positioned in the incision to hold tissue away from the surgical site. The retractor blades are generally adjustably mounted on the retractor arms. Preferably the retractor blades are mounted by a clip in a groove or channel in the retractor arms for adjustable movement parallel to the arms. The construction and arrangement of the arm and the groove allow for multiple blades to be mounted or removed to keep the surgical site clear of surrounding tissue.
A problem with present retractors is that the blades once positioned should remain fixed at the adjusted positions. However, due to the necessity of being able to slide the mounting clip holding the blade along the retractor arm, a tongue on the clip that fits into groove must move freely. The clip is generally spring loaded so that it securely clamps and holds the tongue on the clip in the groove at the adjusted position.
However, because the tongue is smaller than the groove the adjusted position is not as secure as desired. Since the tongue is smaller than the groove it can accidentally move and possibly interfere with the surgery. Therefore, it would be advantageous if an improved clip could be provided to substantially prevent movement of the blades once they are placed, adjusted, and securely positioned to hold tissue away from the surgical site.
It is, therefore, one object of the present invention to provide an improved locking mechanism to securely hold retractor blades in position once they are placed.
Another object of the present invention is to provide an improved blade mounting clip that securely holds a blade in position once the clip is positioned and released in the groove.
Still another object of the present invention is to provide an improved clip having the tongue with a beveled edge which when released engages an edge of the groove substantially preventing the clip and the adjusted position of the blade from changing.
Yet another object of the present invention is to provide an improved blade mounting clip having a tongue shaped to securely hold a blade in position in a substantially square cornered groove.